Circuit boards for electronic equipment commonly include thereon electrostatic sensitive devices. Such devices may well be damaged by static voltages of as little as 200 v., or about one order less than the static voltages that may be generated by persons in a relatively dry atmosphere. It is a preferred practice to enclose such circuit boards within a Faraday shield maintained at ground potential. However, it will be appreciated that where such circuit boards are in transit, particularly by common carrier, less than ideal handling conditions will be encountered, and a convenient grounding circuit may be available.
The circuit boards may also be subject to mechanical damage, particularly in the condition spoken of where they are transported by common carrier.
It is known to provide foam cushioning for the transporation of electrostatic sensitive devices. Generally speaking, foam cushioning may, under mechanical action, generate high static potentials. For this reason it is normally treated with an antistatic agent which reduces the surface resistivity of the material to below about 10.sup.14 ohms/sq., and which thus acts to limit the formation of electrostatic charges. Agents used to promote anti-static properties may be somewhat fugitive, and as a consequence they may not provide the desired protection against the generation of static charges.